Outlet valve for centrifugal separators



April 21, 1925. 1,534,604

G.TER MEER OUTLET VALVE FOR CENTRIFUGAL SEPARATORS Filed Feb. 6, 1925 INVENTOR /Z4,

ATTORNEYS Patented Apr. 21, 1925.

GUST-AV TER MEER, OF HANOVER-LINDEN, GERMANY.

OUTLET VALVE FOR CENTRIFUGAL SEPARATORS.

Application filed February 6, 1925. Serial No. 7,429.

To all whom it may concern:

Be it known that I, GUSTAV TJJR a citizen of Germany, and resident of Hanover-Linden, Germany, have invented certain new and useful Improvements in Outlet Valves for Centrifugal Separators, of which the following is a specification.

This invention is an improvement in centrifugal separators and relates more particularly to the means for controlling the escape of effluent liquid.

In the ordinary types of centrifugal separators having non-filtering outer walls, the cleared liquid separated toward the center of the separation chamber, is conducted to a free outlet at a point located as near as possible to the axis of the chamber.

In separators of the type having a filtering peripheral wall the apertures of such wall often become stopped or plugged by the solid matter and the liquid collects toward the center of the chamber and is permitted to escape through an overflow.

The mass to be separated includes solid particles which are of greater specific gravity than the liquid, and for that reason settle against the outer or peripheral wall of the chamber. It often happens that the liquid also contains particles of less specific gravity than that of the liquid, whereby the particles float on the inner' cylindrical surface of the liquid in the separation chamber. Particles which are only slightl heavier than the liquid may also remain oating in the liquid as they move but slowly outwardly under the action of centrifugal force. These floating particles may therefore occur in all zones of the liquid layers and cannot be easily removed by the action of centrifugal force. The particles which are lighter than the liquid and which float upon the inner surface thereof, usually pass out with the liquid overflow and when there is a large percentage of such lighter particles the outfiowing liquid is clouded and the operation of the apparatus unsatisfactory.

The object of my invention is to avoid the disadvantages above referred to and to accomplish this I provide one or more outlets for the liquid, sopositioned that they draw from a liquid zone at a greater radlal distance from the axis than is the inner liquid surface. As the lighter particles move toward the inner surface and the heavier particles move toward the outer surface of may form a tangentor a secant adjacent to the bottom or the liquid, I position the outlet or outlets so as to draw from the zone where the liquid is the clearest. To accomplish this I construct the outletor outlets as valves which may be operated manually or mechanically, or which may operate as air valves, and by fluid pressure. Such valves may be arranged in various ways, and may be of various types of construction. If fluid pressure valves are employed they may operate on slight pressure differences, and deliver through very small slits which may be only a fraction of a millimeter in width. With such small outlets it will be evident that particles floating in the liquid and of substantially the same specific gravity as the liquid, will be held back as the valve opens and only the almost pure liquid pass through.

The valve or valves can be so arranged that their pivots or axes lie at a right angle or an acuate angle to the axis of the separator and the lengthwise slit of each valve to the annular liquid zone. The valves may also form a plate or a portion of a ring, cylinder, or cone coaxial with the separation chamher. The valves may be so positioned that they may be or may not be influenced by centrifugal force. In the latter case the valve should be weighted in any suitable manner by springs or a lever which is influenced by centrifugal force.

In order to catch such floating particles as may pass the valves a separate filtering arrangement may be provided in which such fine particles are collected.

It will be obvious that my invention may be applied in various different ways, and therefore I desire that the constructions shown in the accompanying drawings be considered in an illustrative, rather than a limiting sense.

In these drawings:

Figs. 1 to 4 inclusive show central vertical sections through four different embodiments of my invention and illustrate the main features of the separation chamber only diagrammatically.

In the construction shown in Fig. 1, the sludge or other material to be separated is carried into the separation chamber through an inlet pipe I delivered at a point closely floor 2. By reason of the centrifugal action this delivered liquid travels up an imperforate peripheral liquid.

wall 3, and collects against the latter in substantially the form of a parabola, while the liquid forms an inner zone with a substantially cylindrical inner surface. The liquid will of course include a series of annular concentric zones of varying purity. The same effect is produced in a separator having a filtering peripheral wall after the passages of the latter become substantially or wholly closed by solid particles.

The cover or top wall l of the usual separation chamber is of annular form and constitutes a. ledge with the inner edge serving as an annular overflow surface for the In my improved construction asshown in Fig. 1, the cover or top wall 4; is provided with an annular opening 5 which may be I ceeds that by which made up of an annular series of small openings or a single annular opening. There may be a plurality of such openings or series of openings at different distances from the axis of rotation.

At the outer side of the opening 5 there is provided an annular flange or wall 6 against which rests the free edge of a rubber ring or annular flap 7 which is secured at its inner edge to the cover 4. The rubber ring constitutes a flap valve and is sub1ect to the action of centrifugal force so as to normally keep the opening 5 tightly closed.

In operation it will be seen that the liquids or solids in the chamber cannot leave through the opening until the pressure exthe flap valve is held closed. When the chamber fills upto the line X the liquid will reach the opening but none of the liquid will pass out through said opening until the layer of liquid has increased su stantially to the line Y. Now the pressure of the liquid between the lines X and Y will be sufficient to overcome the pressure holding the fluid valve closed and the valve will open very slightly to permit the escape of liquid. It will be apparent that the articles of lighter specific gravity than the iquid will be in the zone of liquid indicated approximately by the line Y, and that the liquid zone in the region of the opening 5 will be between the outer and inner surfaces of the liquid and will have the least amount of particles of either lighter or heavier specific gravity. The lighter particles in the zone Y will thus be retained as well as the heavier particles, against the wall 3. The parts may be so designed that the rubber flap opens to only a fraction of a millimeter and permits the outfiowing of the liquid through a very narrow slit. This in itself tends to hold back particles which may float in the liquid, and of substantially the same specific gravity as the liquid.

In order to catch any possible suspended particles which pass through the openings 5, there is preferably provided a filter 9 between the cover 4 and the final liquid outlet 8. This opening 8 is at a greater distance from the axis of rotation than the opening 5,

.and the filter 9 may thus be of substantially cylindrical form and of intermediate ameter. The articles collected on the filter 9 maybe again passed through the apparatus for another separation.

In Fig. 2 I have shown a similar arrangement but the flap valve 7 a is of substantially cylindrical form and stretched between its upper and lower ends so as to be subject to the full power of the centrifugal force. Intermediate of its upper and lower edges thereis provided a divided bridge 10 whereby the liquid in escaping past the valve must flow inward radially through the assage l1 and around the edge of the bri ge to the final outlet 8. This inward flow to the valve and'against the action of centrifugal force tends to facilitate a further clearing of the liquid. Preferably the top wall of the chamber has inwardly directed flanges above and below the valve plate 7 which thereby forms the peripheral wall of an annular chamber 12. By means of this construction it is possible to place liquid in this annular chamber to any extent desired, and the ac tion of centrifugal force on this liquid will tend to hold the valve 7 to its seat. By varying the quantity of liquid in the chamber 12 the pressure of the valve against its seat may be varied, and therefore the depth of liquid between the lines X and Y necessary to open the valve, may be correspondingly varied and the inner cylindrical surface. of the liquid brought to any desired distance inwardly from the valve seat.

In Fig. 3 I have shown a construction in which the flap valve 7 is also subject to the action of centrifugal force but is of approximately conical form and acts against a conical wall 6 in which is placed the outlet opening 5.

In Fig. 4 I have shown a construction in which there are provided two separate outlet valves at different radial distances from the axis. The outer valve 7 may be substantially the same as that shown in Fig. 1, while the inner valve 7 may be similar to that shown in Fig. 2. The inner valve 7 may operate to permit the escape of thin liquid, while the thicker liquid may escape at the outer valve 7. This apparatus may be arranged for continuous operation and the outer valve so regulated that it will not open until a sufficiently high pressure is exerted which would correspond to that required to open the inner valve. With this apparatus the operation may be continuous so long as the thin liquid is discharged through the inner valve.

My invention is not limited to the specific forms illustrated, but includes all constructions by which the discharge of liquids and solids from the separator takes place at points which lie in the zone in which the liquid does not contain any fluid particles, but at most only suspended matter.

For some constructions of separators the inflow of the sludge and the outlet valves may be provided at other places than those shown, for instance in the floor of the separation chamber. I

Having thus described-my invention, what I claim as new and desire to secure by Letters Patent is 1. A centrifugal separator having a separation chamber provided with an. outlet spaced inwardly from the outer wall, and a valve controlling the same, said valve auto matically opening upon the accumulation of liquid to a predetermined distance inward radially from said valve, whereby solid particles of lighter specific gravity than the liquid may accumulate in the inner zone, and solid particles of heavier specific. grav ity than the liquid may accumulate in the outer zone, while the clearest liquid may escape from the intermediate zone.

2. A centrifugal separator having a separation chamber provided with an annular flap valve spaced inwardly from the outer wall thereof, and opening against centrifugal force to present a narrow slit for liquid escape, by the action of predetermined pressure of liquid nearer to the axis than is said valve.

3. A centrifugal separator having a separation chamber provided with an annular end wall having an outlet opening intermediateof its inner and outer edges, and

a valve for controlling said outlet and opening by the action of fluid pressure and tending to close under the action of centrifugal force.

4. A centrifugal separator having a separation chamber provided with an annular end wall having an outlet opening intermediate of its inner and outer edges, and a valve for controlling said outlet and openin by the action of the pressure of the zone 0 liquid between said valve and the inner edge of said'end wall.

5. A centrifugal separator having a separation chamber provided with a peripheral Wall and an annular top wall havin an annular overflow edge spaced inward y from the peripheral wall, said top;1 wall having an outlet intermediate of t e peripheral wall and said overflow edge, and a valve for controlling said outlet.

6. A construction as defined in claim 5, in which the valve is movable to closed position in a direction having an outward radial component whereby the action of centrifugal force directly on the valve tends to hold it in closed position.

-7. A construction as defined in claim 5, in which the valve may move outwardly to open the outlet from said chamber, whereby the pressure of liquid in the chamber tends to open said valve when the depth of liquid inwardly from the peripheral wall exceeds by a predetermined amount the distance from said outlet to said peripheral wall.

' 8. A centrifugal separator having a separation chamber provided with an annular end wall having a plurality of outlet openings intermediate of the outer and inner edges and at different distances from the center, and separate valves controllin said outlets and opening by the action 0 fluid pressure and tending to close under the action of centrifugal force.-

9. A centrifugal separator having a separation chamber provided with a plurality of annular flap valves spaced at different distances inwardly from the outer wall thereof, and each opening against centrifugal force to present a narrow slit for liquid escaping by the action of predetermined pressure of liquid nearer to the axis than said valves.

10. A centrifugal separator having a separation chamber provided with an annular end wall having an outlet intermediate of its inner and outer edges, a valve formed of flexible material anchored at the side 0 said outlet nearer to the center of rotation, the opposite edge of said valve being free and the body portion of said valve opening outwardly from said chamber by the action of predetermined fluid pressure within the chamber and normally held against said outlet by the action of centrifugal force on said valve.

Signed at Bremen, in the Free State of Bremen and Republic of Germany this 19th day of January A. D. 1925 DR. GUSTAV 'rnn MEER; Signed in the presence of:

FRANCIS J DUGAN, Lon S. GRESHAM. 

